# Class SystemProperty (5.0.3)

    public class SystemProperty

Global system properties which are set by App Engine.


Example code:


     if (SystemProperty.environment.value() == SystemProperty.Environment.Value.Production) {
       // do something that's production-only
     }
     String version = SystemProperty.version.get();
     
## Inheritance

[java.lang.Object](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html) \> SystemProperty

## Inherited Members

[Object.clone()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#clone--) [Object.equals(Object)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#equals-java.lang.Object-) [Object.finalize()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#finalize--) [Object.getClass()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#getClass--) [Object.hashCode()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#hashCode--) [Object.notify()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notify--) [Object.notifyAll()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#notifyAll--) [Object.toString()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#toString--) [Object.wait()](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait--) [Object.wait(long)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-) [Object.wait(long,int)](https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#wait-long-int-)

## Static Fields

### applicationId

    public static final SystemProperty applicationId

The application identifier for the current application. Has the
key, `"com.google.appengine.application.id"`.

| **Field Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.utils.SystemProperty` |   |

### applicationVersion

    public static final SystemProperty applicationVersion

The version identifier for the current application version. Result is of
the form


| **Field Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.utils.SystemProperty` |   |

### environment

    public static final SystemProperty.Environment environment

The current executing environment. Has the key,
`"com.google.appengine.runtime.environment"`.
Has the values `"Production"` and `"Development"`.

| **Field Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.utils.SystemProperty.Environment` |   |

### instanceReplicaId (deprecated)

    public static final SystemProperty instanceReplicaId

**Deprecated.** *Use [com.google.appengine.api.modules.ModulesService#getCurrentInstanceId()](https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.modules.ModulesService#com_google_appengine_api_modules_ModulesService_getCurrentInstanceId__)*

| **Field Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.utils.SystemProperty` |   |

### version

    public static final SystemProperty version

The current executing runtime version. Has the key,
`"com.google.appengine.runtime.version"`.
A Version value is composed of period-separated integers, for example,
"1.2.8".

| **Field Value** ||
|---|---|
| **Type** | **Description** |
| `https://docs.cloud.google.com/appengine/docs/standard/java-gen2/reference/services/bundled/latest/com.google.appengine.api.utils.SystemProperty` |   |

## Methods

### get()

    public @Nullable String get()

Gets the value of the system property.
Equivalent to `System.getProperty(key())`.

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/lang/@org/jspecify/annotations/Nullable String.html` |   |

### key()

    public String key()

The key for the system property.

| **Returns** ||
|---|---|
| **Type** | **Description** |
| `https://docs.oracle.com/javase/8/docs/api/java/lang/String.html` |   |

### set(String value)

    public void set(String value)

Sets the value of the system property.
Equivalent to `System.setProperty(key(), value)`.

| **Parameter** ||
|---|---|
| **Name** | **Description** |
| `value` | `https://docs.oracle.com/javase/8/docs/api/java/lang/String.html` |